Since the advent of the Internet, there has been a rapid increase in the interconnectedness of devices capable of storing, processing and communicating data. Now, with the development of what is called the Internet of Things (IoT), devices which were not conventionally equipped to store, process and communicate data are becoming so equipped. For example, a heating system in the home may gather information from various temperature sensors and control the activation of heaters based on the gathered information; a factory pollution monitoring sensor may gather information from various chemical sensors and arrange maintenance based on the gathered information; while a healthcare provider may use wireless sensors, such as heart rate monitors, to track the health of patients while they are at home.
A further example is that of a domestic refrigerator that is provided with the capability to recognise encoded data associated with a perishable food item, store the data in device storage, and subsequently, on being triggered by a program that monitored the data, warn a user over a network to a smartphone of an impending “use by” date for the food item. For the purposes of the present disclosure, such devices will be referred to as “data processing devices”, as they are capable of processing data in some way, even though they may have other, primary functions, as in the refrigerator example.
There are ever-increasing numbers of such devices within the home, office buildings or the outdoor environment that have data processing and communication capabilities which allow such devices to interact with other data processing devices and cloud services. Everyday objects and relatively small scale data processing devices may be connected to each other and to central platforms as part of the IoT.
Typically, such data processing devices need to receive digital content by online means such as over the Internet or an intranet, or by offline means, such as from a digital recording device or medium, such as a data-stick. The digital content may comprise data or executable entities, such as firmware to control the operation of the data processing device itself. Typically, digital content is accompanied by, and has its downstream activity controlled by, a manifest—that is, a metadata file in a format that can be recognised and acted upon by a receiver device in its subsequent handling of the digital content.
Numerous difficulties are faced by those implementing ways of distributing and controlling digital content—for example, there are always questions as to the trustworthiness of content, it may be necessary to time the enablement of the digital content, multiple provider organizations of parts of the content may need to have their individual content items coordinated while the organisations remain separate and independent. It is important also to protect devices from accidental misconfiguration by ensuring that they only update their configuration data with appropriate updates. Further, the nature of the IoT environment is such that it is impossible to secure the entire IoT infrastructure, and thus there is a need to prevent malicious activity hidden in the distribution of digital content. For example, in certain circumstances, networks that include devices that have installed malicious content may be open to man-in-the-middle attacks.
These and numerous other difficulties are faced by those of skill in the data processing art who work in the field of processing of received digital content by data processing devices.